<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title></title>
	<script type="text/javascript">
		var nums = [12,10,5,14,7,43,12,456,55,16,24,56,72];
		var arr = nums.filter(function(value,index,array){
			// console.log(value,index);
			// console.log(array);
			return value<20;
		});
		console.log(arr);

	</script>
</head>
<body>

</body>
</html>